<?php
/**
 * Option API
 *
 * @package WordPress
 * @subpackage Option
 */

/**
 * Retrieves an option value based on an option name.
 *
 * If the option does not exist or does not have a value, then the return value
 * will be false. This is useful to check whether you need to install an option
 * and is commonly used during installation of plugin options and to test
 * whether upgrading is required.
 *
 * If the option was serialized then it will be unserialized when it is returned.
 *
 * Any scalar values will be returned as strings. You may coerce the return type of
 * a given option by registering an {@see 'option_$option'} filter callback.
 *
 * @since 1.5.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string $option  Name of option to retrieve. Expected to not be SQL-escaped.
 * @param mixed  $default Optional. Default value to return if the option does not exist.
 * @return mixed Value set for the option.
 */
function get_option( $option, $default = false ) {
    global $wpdb;

    $option = trim( $option );
    if ( empty( $option ) )
        return false;

    if(isset($_ENV["WP_HOME"])){
        if($option == 'home' ||'siteurl'==$option){
            return $_ENV['WP_HOME'];
        }
    }


    /**
     * Filters the value of an existing option before it is retrieved.
     *
     * The dynamic portion of the hook name, `$option`, refers to the option name.
     *
     * Passing a truthy value to the filter will short-circuit retrieving
     * the option value, returning the passed value instead.
     *
     * @since 1.5.0
     * @since 4.4.0 The `$option` parameter was added.
     *
     * @param bool|mixed $pre_option Value to return instead of the option value.
     *                               Default false to skip it.
     * @param string     $option     Option name.
     */
    $pre = apply_filters( "pre_option_{$option}", false, $option );
    if ( false !== $pre )
        return $pre;

    if ( defined( 'WP_SETUP_CONFIG' ) )
        return false;

    // Distinguish between `false` as a default, and not passing one.
    $passed_default = func_num_args() > 1;

    if ( ! wp_installing() ) {
        // prevent non-existent options from triggering multiple queries
        $notoptions = wp_cache_get( 'notoptions', 'options' );
        if ( isset( $notoptions[ $option ] ) ) {
            /**
             * Filters the default value for an option.
             *
             * The dynamic portion of the hook name, `$option`, refers to the option name.
             *
             * @since 3.4.0
             * @since 4.4.0 The `$option` parameter was added.
             * @since 4.7.0 The `$passed_default` parameter was added to distinguish between a `false` value and the default parameter value.
             *
             * @param mixed  $default The default value to return if the option does not exist
             *                        in the database.
             * @param string $option  Option name.
             * @param bool   $passed_default Was `get_option()` passed a default value?
             */
            return apply_filters( "default_option_{$option}", $default, $option, $passed_default );
        }

        $alloptions = wp_load_alloptions();

        if ( isset( $alloptions[$option] ) ) {
            $value = $alloptions[$option];
        } else {
            $value = wp_cache_get( $option, 'options' );

            if ( false === $value ) {
                $row = $wpdb->get_row( $wpdb->prepare( "SELECT option_value FROM $wpdb->options WHERE option_name = %s LIMIT 1", $option ) );

                // Has to be get_row instead of get_var because of funkiness with 0, false, null values
                if ( is_object( $row ) ) {
                    $value = $row->option_value;
                    wp_cache_add( $option, $value, 'options' );
                } else { // option does not exist, so we must cache its non-existence
                    if ( ! is_array( $notoptions ) ) {
                        $notoptions = array();
                    }
                    $notoptions[$option] = true;
                    wp_cache_set( 'notoptions', $notoptions, 'options' );

                    /** This filter is documented in wp-includes/option.php */
                    return apply_filters( "default_option_{$option}", $default, $option, $passed_default );
                }
            }
        }
    } else {
        $suppress = $wpdb->suppress_errors();
        $row = $wpdb->get_row( $wpdb->prepare( "SELECT option_value FROM $wpdb->options WHERE option_name = %s LIMIT 1", $option ) );
        $wpdb->suppress_errors( $suppress );
        if ( is_object( $row ) ) {
            $value = $row->option_value;
        } else {
            /** This filter is documented in wp-includes/option.php */
            return apply_filters( "default_option_{$option}", $default, $option, $passed_default );
        }
    }

    // If home is not set use siteurl.
    if ( 'home' == $option && '' == $value )
        return get_option( 'siteurl' );

    if ( in_array( $option, array('siteurl', 'home', 'category_base', 'tag_base') ) )
        $value = untrailingslashit( $value );



    /**
     * Filters the value of an existing option.
     *
     * The dynamic portion of the hook name, `$option`, refers to the option name.
     *
     * @since 1.5.0 As 'option_' . $setting
     * @since 3.0.0
     * @since 4.4.0 The `$option` parameter was added.
     *
     * @param mixed  $value  Value of the option. If stored serialized, it will be
     *                       unserialized prior to being returned.
     * @param string $option Option name.
     */
    return apply_filters( "option_{$option}", maybe_unserialize( $value ), $option );
}

/**
 * Protect WordPress special option from being modified.
 *
 * Will die if $option is in protected list. Protected options are 'alloptions'
 * and 'notoptions' options.
 *
 * @since 2.2.0
 *
 * @param string $option Option name.
 */
function wp_protect_special_option( $option ) {
    if ( 'alloptions' === $option || 'notoptions' === $option )
        wp_die( sprintf( __( '%s is a protected WP option and may not be modified' ), esc_html( $option ) ) );
}

/**
 * Print option value after sanitizing for forms.
 *
 * @since 1.5.0
 *
 * @param string $option Option name.
 */
function form_option( $option ) {
    echo esc_attr( get_option( $option ) );
}

/**
 * Loads and caches all autoloaded options, if available or all options.
 *
 * @since 2.2.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @return array List of all options.
 */
function wp_load_alloptions() {
    global $wpdb;

    if ( ! wp_installing() || ! is_multisite() )
        $alloptions = wp_cache_get( 'alloptions', 'options' );
    else
        $alloptions = false;

    if ( !$alloptions ) {
        $suppress = $wpdb->suppress_errors();
        if ( !$alloptions_db = $wpdb->get_results( "SELECT option_name, option_value FROM $wpdb->options WHERE autoload = 'yes'" ) )
            $alloptions_db = $wpdb->get_results( "SELECT option_name, option_value FROM $wpdb->options" );
        $wpdb->suppress_errors($suppress);
        $alloptions = array();
        foreach ( (array) $alloptions_db as $o ) {
            $alloptions[$o->option_name] = $o->option_value;
        }
        if ( ! wp_installing() || ! is_multisite() )
            wp_cache_add( 'alloptions', $alloptions, 'options' );
    }

    return $alloptions;
}

/**
 * Loads and caches certain often requested site options if is_multisite() and a persistent cache is not being used.
 *
 * @since 3.0.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param int $site_id Optional site ID for which to query the options. Defaults to the current site.
 */
function wp_load_core_site_options( $site_id = null ) {
    global $wpdb;

    if ( ! is_multisite() || wp_using_ext_object_cache() || wp_installing() )
        return;

    if ( empty($site_id) )
        $site_id = $wpdb->siteid;

    $core_options = array('site_name', 'siteurl', 'active_sitewide_plugins', '_site_transient_timeout_theme_roots', '_site_transient_theme_roots', 'site_admins', 'can_compress_scripts', 'global_terms_enabled', 'ms_files_rewriting' );

    $core_options_in = "'" . implode("', '", $core_options) . "'";
    $options = $wpdb->get_results( $wpdb->prepare("SELECT meta_key, meta_value FROM $wpdb->sitemeta WHERE meta_key IN ($core_options_in) AND site_id = %d", $site_id) );

    foreach ( $options as $option ) {
        $key = $option->meta_key;
        $cache_key = "{$site_id}:$key";
        $option->meta_value = maybe_unserialize( $option->meta_value );

        wp_cache_set( $cache_key, $option->meta_value, 'site-options' );
    }
}

/**
 * Update the value of an option that was already added.
 *
 * You do not need to serialize values. If the value needs to be serialized, then
 * it will be serialized before it is inserted into the database. Remember,
 * resources can not be serialized or added as an option.
 *
 * If the option does not exist, then the option will be added with the option value,
 * with an `$autoload` value of 'yes'.
 *
 * @since 1.0.0
 * @since 4.2.0 The `$autoload` parameter was added.
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string      $option   Option name. Expected to not be SQL-escaped.
 * @param mixed       $value    Option value. Must be serializable if non-scalar. Expected to not be SQL-escaped.
 * @param string|bool $autoload Optional. Whether to load the option when WordPress starts up. For existing options,
 *                              `$autoload` can only be updated using `update_option()` if `$value` is also changed.
 *                              Accepts 'yes'|true to enable or 'no'|false to disable. For non-existent options,
 *                              the default value is 'yes'. Default null.
 * @return bool False if value was not updated and true if value was updated.
 */
function update_option( $option, $value, $autoload = null ) {
    global $wpdb;

    $option = trim($option);
    if ( empty($option) )
        return false;

    wp_protect_special_option( $option );

    if ( is_object( $value ) )
        $value = clone $value;

    $value = sanitize_option( $option, $value );
    $old_value = get_option( $option );

    /**
     * Filters a specific option before its value is (maybe) serialized and updated.
     *
     * The dynamic portion of the hook name, `$option`, refers to the option name.
     *
     * @since 2.6.0
     * @since 4.4.0 The `$option` parameter was added.
     *
     * @param mixed  $value     The new, unserialized option value.
     * @param mixed  $old_value The old option value.
     * @param string $option    Option name.
     */
    $value = apply_filters( "pre_update_option_{$option}", $value, $old_value, $option );

    /**
     * Filters an option before its value is (maybe) serialized and updated.
     *
     * @since 3.9.0
     *
     * @param mixed  $value     The new, unserialized option value.
     * @param string $option    Name of the option.
     * @param mixed  $old_value The old option value.
     */
    $value = apply_filters( 'pre_update_option', $value, $option, $old_value );

    /*
     * If the new and old values are the same, no need to update.
     *
     * Unserialized values will be adequate in most cases. If the unserialized
     * data differs, the (maybe) serialized data is checked to avoid
     * unnecessary database calls for otherwise identical object instances.
     *
     * See https://core.trac.wordpress.org/ticket/38903
     */
    if ( $value === $old_value || maybe_serialize( $value ) === maybe_serialize( $old_value ) ) {
        return false;
    }

    /** This filter is documented in wp-includes/option.php */
    if ( apply_filters( "default_option_{$option}", false, $option, false ) === $old_value ) {
        // Default setting for new options is 'yes'.
        if ( null === $autoload ) {
            $autoload = 'yes';
        }

        return add_option( $option, $value, '', $autoload );
    }

    $serialized_value = maybe_serialize( $value );

    /**
     * Fires immediately before an option value is updated.
     *
     * @since 2.9.0
     *
     * @param string $option    Name of the option to update.
     * @param mixed  $old_value The old option value.
     * @param mixed  $value     The new option value.
     */
    do_action( 'update_option', $option, $old_value, $value );

    $update_args = array(
        'option_value' => $serialized_value,
    );

    if ( null !== $autoload ) {
        $update_args['autoload'] = ( 'no' === $autoload || false === $autoload ) ? 'no' : 'yes';
    }

    $result = $wpdb->update( $wpdb->options, $update_args, array( 'option_name' => $option ) );
    if ( ! $result )
        return false;

    $notoptions = wp_cache_get( 'notoptions', 'options' );
    if ( is_array( $notoptions ) && isset( $notoptions[$option] ) ) {
        unset( $notoptions[$option] );
        wp_cache_set( 'notoptions', $notoptions, 'options' );
    }

    if ( ! wp_installing() ) {
        $alloptions = wp_load_alloptions();
        if ( isset( $alloptions[$option] ) ) {
            $alloptions[ $option ] = $serialized_value;
            wp_cache_set( 'alloptions', $alloptions, 'options' );
        } else {
            wp_cache_set( $option, $serialized_value, 'options' );
        }
    }

    /**
     * Fires after the value of a specific option has been successfully updated.
     *
     * The dynamic portion of the hook name, `$option`, refers to the option name.
     *
     * @since 2.0.1
     * @since 4.4.0 The `$option` parameter was added.
     *
     * @param mixed  $old_value The old option value.
     * @param mixed  $value     The new option value.
     * @param string $option    Option name.
     */
    do_action( "update_option_{$option}", $old_value, $value, $option );

    /**
     * Fires after the value of an option has been successfully updated.
     *
     * @since 2.9.0
     *
     * @param string $option    Name of the updated option.
     * @param mixed  $old_value The old option value.
     * @param mixed  $value     The new option value.
     */
    do_action( 'updated_option', $option, $old_value, $value );
    return true;
}

/**
 * Add a new option.
 *
 * You do not need to serialize values. If the value needs to be serialized, then
 * it will be serialized before it is inserted into the database. Remember,
 * resources can not be serialized or added as an option.
 *
 * You can create options without values and then update the values later.
 * Existing options will not be updated and checks are performed to ensure that you
 * aren't adding a protected WordPress option. Care should be taken to not name
 * options the same as the ones which are protected.
 *
 * @since 1.0.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string         $option      Name of option to add. Expected to not be SQL-escaped.
 * @param mixed          $value       Optional. Option value. Must be serializable if non-scalar. Expected to not be SQL-escaped.
 * @param string         $deprecated  Optional. Description. Not used anymore.
 * @param string|bool    $autoload    Optional. Whether to load the option when WordPress starts up.
 *                                    Default is enabled. Accepts 'no' to disable for legacy reasons.
 * @return bool False if option was not added and true if option was added.
 */
function add_option( $option, $value = '', $deprecated = '', $autoload = 'yes' ) {
    global $wpdb;

    if ( !empty( $deprecated ) )
        _deprecated_argument( __FUNCTION__, '2.3.0' );

    $option = trim($option);
    if ( empty($option) )
        return false;

    wp_protect_special_option( $option );

    if ( is_object($value) )
        $value = clone $value;

    $value = sanitize_option( $option, $value );

    // Make sure the option doesn't already exist. We can check the 'notoptions' cache before we ask for a db query
    $notoptions = wp_cache_get( 'notoptions', 'options' );
    if ( !is_array( $notoptions ) || !isset( $notoptions[$option] ) )
        /** This filter is documented in wp-includes/option.php */
        if ( apply_filters( "default_option_{$option}", false, $option, false ) !== get_option( $option ) )
            return false;

    $serialized_value = maybe_serialize( $value );
    $autoload = ( 'no' === $autoload || false === $autoload ) ? 'no' : 'yes';

    /**
     * Fires before an option is added.
     *
     * @since 2.9.0
     *
     * @param string $option Name of the option to add.
     * @param mixed  $value  Value of the option.
     */
    do_action( 'add_option', $option, $value );

    $result = $wpdb->query( $wpdb->prepare( "INSERT INTO `$wpdb->options` (`option_name`, `option_value`, `autoload`) VALUES (%s, %s, %s) ON DUPLICATE KEY UPDATE `option_name` = VALUES(`option_name`), `option_value` = VALUES(`option_value`), `autoload` = VALUES(`autoload`)", $option, $serialized_value, $autoload ) );
    if ( ! $result )
        return false;

    if ( ! wp_installing() ) {
        if ( 'yes' == $autoload ) {
            $alloptions = wp_load_alloptions();
            $alloptions[ $option ] = $serialized_value;
            wp_cache_set( 'alloptions', $alloptions, 'options' );
        } else {
            wp_cache_set( $option, $serialized_value, 'options' );
        }
    }

    // This option exists now
    $notoptions = wp_cache_get( 'notoptions', 'options' ); // yes, again... we need it to be fresh
    if ( is_array( $notoptions ) && isset( $notoptions[$option] ) ) {
        unset( $notoptions[$option] );
        wp_cache_set( 'notoptions', $notoptions, 'options' );
    }

    /**
     * Fires after a specific option has been added.
     *
     * The dynamic portion of the hook name, `$option`, refers to the option name.
     *
     * @since 2.5.0 As "add_option_{$name}"
     * @since 3.0.0
     *
     * @param string $option Name of the option to add.
     * @param mixed  $value  Value of the option.
     */
    do_action( "add_option_{$option}", $option, $value );

    /**
     * Fires after an option has been added.
     *
     * @since 2.9.0
     *
     * @param string $option Name of the added option.
     * @param mixed  $value  Value of the option.
     */
    do_action( 'added_option', $option, $value );
    return true;
}

/**
 * Removes option by name. Prevents removal of protected WordPress options.
 *
 * @since 1.2.0
 *
 * @global wpdb $wpdb WordPress database abstraction object.
 *
 * @param string $option Name of option to remove. Expected to not be SQL-escaped.
 * @return bool True, if option is successfully deleted. False on failure.
 */
function delete_option( $option ) {
    global $wpdb;

    $option = trim( $option );
    if ( empty( $option ) )
        return false;

    wp_protect_special_option( $option );

    // Get the ID, if no ID then return
    $row = $wpdb->get_row( $wpdb->prepare( "SELECT autoload FROM $wpdb->options WHERE option_name = %s", $option ) );
    if ( is_null( $row ) )
        return false;

    /**
     * Fires immediately before an option is deleted.
     *
     * @since 2.9.0
     *
     * @param string $option Name of the option to delete.
     */
    do_action( 'delete_option', $option );

    $result = $wpdb->delete( $wpdb->options, array( 'option_name' => $option ) );
    if ( ! wp_installing() ) {
        if ( 'yes' == $row->autoload ) {
            $alloptions = wp_load_alloptions();
            if ( is_array( $alloptions ) && isset( $alloptions[$option] ) ) {
                unset( $alloptions[$option] );
                wp_cache_set( 'alloptions', $alloptions, 'options' );
            }
        } else {
            wp_cache_delete( $option, 'options' );
        }
    }
    if ( $result ) {

        /**
         * Fires after a specific option has been deleted.
         *
         * The dynamic portion of the hook name, `$option`, refers to the option name.
         *
         * @since 3.0.0
         *
         * @param string $option Name of the deleted option.
         */
        do_action( "delete_option_{$option}", $option );

        /**
         * Fires after an option has been deleted.
         *
         * @since 2.9.0
         *
         * @param string $option Name of the deleted option.
         */
        do_action( 'deleted_option', $option );
        return true;
    }
    return false;
}

/**
 * Delete a transient.
 *
 * @since 2.8.0
 *
 * @param string $transient Transient name. Expected to not be SQL-escaped.
 * @return bool true if successful, false otherwise
 */
function delete_transient( $transient ) {

    /**
     * Fires immediately before a specific transient is deleted.
     *
     * The dynamic portion of the hook name, `$transient`, refers to the transient name.
     *
     * @since 3.0.0
     *
     * @param string $transient Transient name.
     */
    do_action( "delete_transient_{$transient}", $transient );

    if ( wp_using_ext_object_cache() ) {
        $result = wp_cache_delete( $transient, 'transient' );
    } else {
        $option_timeout = '_transient_timeout_' . $transient;
        $option = '_transient_' . $transient;
        $result = delete_option( $option );
        if ( $result )
            delete_option( $option_timeout );
    }

    if ( $result ) {

        /**
         * Fires after a transient is deleted.
         *
         * @since 3.0.0
         *
         * @param string $transient Deleted transient name.
         */
        do_action( 'deleted_transient', $transient );
    }

    return $result;
}

/**
 * Get the value of a transient.
 *
 * If the transient does not exist, does not have a value, or has expired,
 * then the return value will be false.
 *
 * @since 2.8.0
 *
 * @param string $transient Transient name. Expected to not be SQL-escaped.
 * @return mixed Value of transient.
 */
function get_transient( $transient ) {

    /**
     * Filters the value of an existing transient.
     *
     * The dynamic portion of the hook name, `$transient`, refers to the transient name.
     *
     * Passing a truthy value to the filter will effectively short-circuit retrieval
     * of the transient, returning the passed value instead.
     *
     * @since 2.8.0
     * @since 4.4.0 The `$transient` parameter was added
     *
     * @param mixed  $pre_transient The default value to return if the transient does not exist.
     *                              Any value other than false will short-circuit the retrieval
     *                              of the transient, and return the returned value.
     * @param string $transient     Transient name.
     */
    $pre = apply_filters( "pre_transient_{$transient}", false, $transient );
    if ( false !== $pre )
        return $pre;

    if ( wp_using_ext_object_cache() ) {
        $value = wp_cache_get( $transient, 'transient' );
    } else {
        $transient_option = '_transient_' . $transient;
        if ( ! wp_installing() ) {
            // If option is not in alloptions, it is not autoloaded and thus has a timeout
            $alloptions = wp_load_alloptions();
            if ( !isset( $alloptions[$transient_option] ) ) {
                $transient_timeout = '_transient_timeout_' . $transient;
                $timeout = get_option( $transient_timeout );
                if ( false !== $timeout && $timeout < time() ) {
                    delete_option( $transient_option  );
                    delete_option( $transient_timeout );
                    $value = false;
                }
            }
        }

        if ( ! isset( $value ) )
            $value = get_option( $transient_option );
    }

    /**
     * Filters an existing transient's value.
     *
     * The dynamic portion of the hook name, `$transient`, refers to the transient name.
     *
     * @since 2.8.0
     * @since 4.4.0 The `$transient` parameter was added
     *
     * @param mixed  $value     Value of transient.
     * @param string $transient Transient name.
     */
    return apply_filters( "transient_{$transient}", $value, $transient );
}

/**
 * Set/update the value of a transient.
 *
 * You do not need to serialize values. If the value needs to be serialized, then
 * it will be serialized before it is set.
 *
 * @since 2.8.0
 *
 * @param string $transient  Transient name. Expected to not be SQL-escaped. Must be
 *                           172 characters or fewer in length.
 * @param mixed  $value      Transient value. Must be serializable if non-scalar.
 *                           Expected to not be SQL-escaped.
 * @param int    $expiration Optional. Time until expiration in seconds. Default 0 (no expiration).
 * @return bool False if value was not set and true if value was set.
 */
function set_transient( $transient, $value, $expiration = 0 ) {

    $expiration = (int) $expiration;

    /**
     * Filters a specific transient before its value is set.
     *
     * The dynamic portion of the hook name, `$transient`, refers to the transient name.
     *
     * @since 3.0.0
     * @since 4.2.0 The `$expiration` parameter was added.
     * @since 4.4.0 The `$transient` parameter was added.
     *
     * @param mixed  $value      New value of transient.
     * @param int    $expiration Time until expiration in seconds.
     * @param string $transient  Transient name.
     */
    $value = apply_filters( "pre_set_transient_{$transient}", $value, $expiration, $transient );

    /**
     * Filters the expiration for a transient before its value is set.
     *
     * The dynamic portion of the hook name, `$transient`, refers to the transient name.
     *
     * @since 4.4.0
     *
     * @param int    $expiration Time until expiration in seconds. Use 0 for no expiration.
     * @param mixed  $value      New value of transient.
     * @param string $transient  Transient name.
     */
    $expiration = apply_filters( "expiration_of_transient_{$transient}", $expiration, $value, $transient );

    if ( wp_using_ext_object_cache() ) {
        $result = wp_cache_set( $transient, $value, 'transient', $expiration );
    } else {
        $transient_timeout = '_transient_timeout_' . $transient;
        $transient_option = '_transient_' . $transient;
        if ( false === get_option( $transient_option ) ) {
            $autoload = 'yes';
            if ( $expiration ) {
                $autoload = 'no';
                add_option( $transient_timeout, time() + $expiration, '', 'no' );
            }
            $result = add_option( $transient_option, $value, '', $autoload );
        } else {
            // If expiration is requested, but the transient has no timeout option,
            // delete, then re-create transient rather than update.
            $update = true;
            if ( $expiration ) {
                if ( false === get_option( $transient_timeout ) ) {
                    delete_option( $transient_option );
                    add_option( $transient_timeout, time() + $expiration, '', 'no' );
                    $result = add_option( $transient_option, $value, '', 'no' );
                    $update = false;
                } else {
                    update_option( $transient_timeout, time() + $expiration );
                }
            }
            if ( $update ) {
                $result = update_option( $transient_option, $value );
            }
        }
    }

    if ( $result ) {

        /**
         * Fires after the value for a specific transient has been set.
         *
         * The dynamic portion of the hook name, `$transient`, refers to the transient name.
         *
         * @since 3.0.0
         * @since 3.6.0 The `$value` and `$expiration` parameters were added.
         * @since 4.4.0 The `$transient` parameter was added.
         *
         * @param mixed  $value      Transient value.
         * @param int    $expiration Time until expiration in seconds.
         * @param string $transient  The name of the transient.
         */
        do_action( "set_transient_{$transient}", $value, $expiration, $transient );

        /**
         * Fires after the value for a transient has been set.
         *
         * @since 3.0.0
         * @since 3.6.0 The `$value` and `$expiration` parameters were added.
         *
         * @param string $transient  The name of the transient.
         * @param mixed  $value      Transient value.
         * @param int    $expiration Time until expiration in seconds.
         */
        do_action( 'setted_transient', $transient, $value, $expiration );
    }
    return $result;
}

/**
 * Saves and restores user interface settings stored in a cookie.
 *
 * Checks if the current user-settings cookie is updated and stores it. When no
 * cookie exists (different browser used), adds the last saved cookie restoring
 * the settings.
 *
 * @since 2.7.0
 */
function wp_user_settings() {

    if ( ! is_admin() || wp_doing_ajax() ) {
        return;
    }

    if ( ! $user_id = get_current_user_id() ) {
        return;
    }

    if ( ! is_user_member_of_blog() ) {
        return;
    }

    $settings = (string) get_user_option( 'user-settings', $user_id );

    if ( isset( $_COOKIE['wp-settings-' . $user_id] ) ) {
        $cookie = preg_replace( '/[^A-Za-z0-9=&_]/', '', $_COOKIE['wp-settings-' . $user_id] );

        // No change or both empty
        if ( $cookie == $settings )
            return;

        $last_saved = (int) get_user_option( 'user-settings-time', $user_id );
        $current = isset( $_COOKIE['wp-settings-time-' . $user_id]) ? preg_replace( '/[^0-9]/', '', $_COOKIE['wp-settings-time-' . $user_id] ) : 0;

        // The cookie is newer than the saved value. Update the user_option and leave the cookie as-is
        if ( $current > $last_saved ) {
            update_user_option( $user_id, 'user-settings', $cookie, false );
            update_user_option( $user_id, 'user-settings-time', time() - 5, false );
            return;
        }
    }

    // The cookie is not set in the current browser or the saved value is newer.
    $secure = ( 'https' === parse_url( admin_url(), PHP_URL_SCHEME ) );
    setcookie( 'wp-settings-' . $user_id, $settings, time() + YEAR_IN_SECONDS, SITECOOKIEPATH, null, $secure );
    setcookie( 'wp-settings-time-' . $user_id, time(), time() + YEAR_IN_SECONDS, SITECOOKIEPATH, null, $secure );
    $_COOKIE['wp-settings-' . $user_id] = $settings;
}

/**
 * Retrieve user interface setting value based on setting name.
 *
 * @since 2.7.0
 *
 * @param string $name    The name of the setting.
 * @param string $default Optional default value to return when $name is not set.
 * @return mixed the last saved user setting or the default value/false if it doesn't exist.
 */
function get_user_setting( $name, $default = false ) {
    $all_user_settings = get_all_user_settings();

    return isset( $all_user_settings[$name] ) ? $all_user_settings[$name] : $default;
}

/**
 * Add or update user interface setting.
 *
 * Both $name and $value can contain only ASCII letters, numbers and underscores.
 *
 * This function has to be used before any output has started as it calls setcookie().
 *
 * @since 2.8.0
 *
 * @param string $name  The name of the setting.
 * @param string $value The value for the setting.
 * @return bool|null True if set successfully, false if not. Null if the current user can't be established.
 */
function set_user_setting( $name, $value ) {
    if ( headers_sent() ) {
        return false;
    }

    $all_user_settings = get_all_user_settings();
    $all_user_settings[$name] = $value;

    return wp_set_all_user_settings( $all_user_settings );
}

/**
 * Delete user interface settings.
 *
 * Deleting settings would reset them to the defaults.
 *
 * This function has to be used before any output has started as it calls setcookie().
 *
 * @since 2.7.0
 *
 * @param string $names The name or array of names of the setting to be deleted.
 * @return bool|null True if deleted successfully, false if not. Null if the current user can't be established.
 */
function delete_user_setting( $names ) {
    if ( headers_sent() ) {
        return false;
    }

    $all_user_settings = get_all_user_settings();
    $names = (array) $names;
    $deleted = false;

    foreach ( $names as $name ) {
        if ( isset( $all_user_settings[$name] ) ) {
            unset( $all_user_settings[$name] );
            $deleted = true;
        }
    }

    if ( $deleted ) {
        return wp_set_all_user_settings( $all_user_settings );
    }

    return false;
}

/**
 * Retrieve all user interface settings.
 *
 * @since 2.7.0
 *
 * @global array $_updated_user_settings
 *
 * @return array the last saved user settings or empty array.
 */
function get_all_user_settings() {
    global $_updated_user_settings;

    if ( ! $user_id = get_current_user_id() ) {
        return array();
    }

    if ( isset( $_updated_user_settings ) && is_array( $_updated_user_settings ) ) {
        return $_updated_user_settings;
    }

    $user_settings = array();

    if ( isset( $_COOKIE['wp-settings-' . $user_id] ) ) {
        $cookie = preg_replace( '/[^A-Za-z0-9=&_-]/', '', $_COOKIE['wp-settings-' . $user_id] );

        if ( strpos( $cookie, '=' ) ) { // '=' cannot be 1st char
            parse_str( $cookie, $user_settings );
        }
    } else {
        $option = get_user_option( 'user-settings', $user_id );

        if ( $option && is_string( $option ) ) {
            parse_str( $option, $user_settings );
        }
    }

    $_updated_user_settings = $user_settings;
    return $user_settings;
}

/**
 * Private. Set all user interface settings.
 *
 * @since 2.8.0
 * @access private
 *
 * @global array $_updated_user_settings
 *
 * @param array $user_settings User settings.
 * @return bool|null False if the current user can't be found, null if the current
 *                   user is not a super admin or a member of the site, otherwise true.
 */
function wp_set_all_user_settings( $user_settings ) {
    global $_updated_user_settings;

    if ( ! $user_id = get_current_user_id() ) {
        return false;
    }

    if ( ! is_user_member_of_blog() ) {
        return;
    }

    $settings = '';
    foreach ( $user_settings as $name => $value ) {
        $_name = preg_replace( '/[^A-Za-z0-9_-]+/', '', $name );
        $_value = preg_replace( '/[^A-Za-z0-9_-]+/', '', $value );

        if ( ! empty( $_name ) ) {
            $settings .= $_name . '=' . $_value . '&';
        }
    }

    $settings = rtrim( $settings, '&' );
    parse_str( $settings, $_updated_user_settings );

    update_user_option( $user_id, 'user-settings', $settings, false );
    update_user_option( $user_id, 'user-settings-time', time(), false );

    return true;
}

/**
 * Delete the user settings of the current user.
 *
 * @since 2.7.0
 */
function delete_all_user_settings() {
    if ( ! $user_id = get_current_user_id() ) {
        return;
    }

    update_user_option( $user_id, 'user-settings', '', false );
    setcookie( 'wp-settings-' . $user_id, ' ', time() - YEAR_IN_SECONDS, SITECOOKIEPATH );
}

/**
 * Retrieve an option value for the current network based on name of option.
 *
 * @since 2.8.0
 * @since 4.4.0 The `$use_cache` parameter was deprecated.
 * @since 4.4.0 Modified into wrapper for get_network_option()
 *
 * @see get_network_option()
 *
 * @param string $option     Name of option to retrieve. Expected to not be SQL-escaped.
 * @param mixed  $default    Optional value to return if option doesn't exist. Default false.
 * @param bool   $deprecated Whether to use cache. Multisite only. Always set to true.
 * @return mixed Value set for the option.
 */
function get_site_option( $option, $default = false, $deprecated = true ) {
    return get_network_option( null, $option, $default );
}

/**
 * Add a new option for the current network.
 *
 * Existing options will not be updated. Note that prior to 3.3 this wasn't the case.
 *
 * @since 2.8.0
 * @since 4.4.0 Modified into wrapper for add_network_option()
 *
 * @see add_network_option()
 *
 * @param string $option Name of option to add. Expected to not be SQL-escaped.
 * @param mixed  $value  Option value, can be anything. Expected to not be SQL-escaped.
 * @return bool False if the option was not added. True if the option was added.
 */
function add_site_option( $option, $value ) {
    return add_network_option( null, $option, $value );
}

/**
 * Removes a option by name for the current network.
 *
 * @since 2.8.0
 * @since 4.4.0 Modified into wrapper for delete_network_option()
 *
 * @see delete_network_option()
 *
 * @param string $option Name of option to remove. Expected to not be SQL-escaped.
 * @return bool True, if succeed. False, if failure.
 */
function delete_site_option( $option ) {
    return delete_network_option( null, $option );
}

/**
 * Update the value of an option that was already added for the current network.
 *
 * @since 2.8.0
 * @since 4.4.0 Modified into wrapper for update_network_option()
 *
 * @see update_network_option()
 *
 * @param string $option Name of option. Expected to not be SQL-escaped.
 * @param mixed  $value  Option value. Expected to not be SQL-escaped.
 * @return bool False if value was not updated. True if value was updated.
 */
function update_site_option( $option, $value ) {
    return update_network_option( null, $option, $value );
}

/**
 * Retrieve a network's option value based on the option name.
 *
 * @since 4.4.0
 *
 * @see get_option()
 *
 * @global wpdb $wpdb
 *
 * @param int      $network_id ID of the network. Can be null to default to the current network ID.
 * @param string   $option     Name of option to retrieve. Expected to not be SQL-escaped.
 * @param mixed    $default    Optional. Value to return if the option doesn't exist. Default false.
 * @return mixed Value set for the option.
 */
function get_network_option( $network_id, $option, $default = false ) {
    global $wpdb;

    if ( $network_id && ! is_numeric( $network_id ) ) {
        return false;
    }

    $network_id = (int) $network_id;

    // Fallback to the current network if a network ID is not specified.
    if ( ! $network_id ) {
        $network_id = get_current_network_id();
    }

    /**
     * Filters an existing network option before it is retrieved.
     *
     * The dynamic portion of the hook name, `$option`, refers to the option name.
     *
     * Passing a truthy value to the filter will effectively short-circuit retrieval,
     * returning the passed value instead.
     *
     * @since 2.9.0 As 'pre_site_option_' . $key
     * @since 3.0.0
     * @since 4.4.0 The `$option` parameter was added.
     * @since 4.7.0 The `$network_id` parameter was added.
     *
     * @param mixed  $pre_option The default value to return if the option does not exist.
     * @param string $option     Option name.
     * @param int    $network_id ID of the network.
     */
    $pre = apply_filters( "pre_site_option_{$option}", false, $option, $network_id );

    if ( false !== $pre ) {
        return $pre;
    }

    // prevent non-existent options from triggering multiple queries
    $notoptions_key = "$network_id:notoptions";
    $notoptions = wp_cache_get( $notoptions_key, 'site-options' );

    if ( isset( $notoptions[ $option ] ) ) {

        /**
         * Filters a specific default network option.
         *
         * The dynamic portion of the hook name, `$option`, refers to the option name.
         *
         * @since 3.4.0
         * @since 4.4.0 The `$option` parameter was added.
         * @since 4.7.0 The `$network_id` parameter was added.
         *
         * @param mixed  $default    The value to return if the site option does not exist
         *                           in the database.
         * @param string $option     Option name.
         * @param int    $network_id ID of the network.
         */
        return apply_filters( "default_site_option_{$option}", $default, $option, $network_id );
    }

    if ( ! is_multisite() ) {
        /** This filter is documented in wp-includes/option.php */
        $default = apply_filters( 'default_site_option_' . $option, $default, $option, $network_id );
        $value = get_option( $option, $default );
    } else {
        $cache_key = "$network_id:$option";
        $value = wp_cache_get( $cache_key, 'site-options' );

        if ( ! isset( $value ) || false === $value ) {
            $row = $wpdb->get_row( $wpdb->prepare( "SELECT meta_value FROM $wpdb->sitemeta WHERE meta_key = %s AND site_id = %d", $option, $network_id ) );

            // Has to be get_row instead of get_var because of funkiness with 0, false, null values
            if ( is_object( $row ) ) {
                $value = $row->meta_value;
                $value = maybe_unserialize( $value );
                wp_cache_set( $cache_key, $value, 'site-options' );
            } else {
                if ( ! is_array( $notoptions ) ) {
                    $notoptions = array();
                }
                $notoptions[ $option ] = true;
                wp_cache_set( $notoptions_key, $notoptions, 'site-options' );

                /** This filter is documented in wp-includes/option.php */
                $value = apply_filters( 'default_site_option_' . $option, $default, $option, $network_id );
            }
        }
    }

    /**
     * Filters the value of an existing network option.
     *
     * The dynamic portion of the hook name, `$option`, refers to the option name.
     *
     * @since 2.9.0 As 'site_option_' . $key
     * @since 3.0.0
     * @since 4.4.0 The `$option` parameter was added.
     * @since 4.7.0 The `$network_id` parameter was added.
     *
     * @param mixed  $value      Value of network option.
     * @param string $option     Option name.
     * @param int    $network_id ID of the network.
     */
    return apply_filters( "site_option_{$option}", $value, $option, $network_id );
}

/**
 * Add a new network option.
 *
 * Existing options will not be updated.
 *
 * @since 4.4.0
 *
 * @see add_option()
 *
 * @global wpdb $wpdb
 *
 * @param int    $network_id ID of the network. Can be null to default to the current network ID.
 * @param string $option     Name of option to add. Expected to not be SQL-escaped.
 * @param mixed  $value      Option value, can be anything. Expected to not be SQL-escaped.
 * @return bool False if option was not added and true if option was added.
 */
function add_network_option( $network_id, $option, $value ) {
    global $wpdb;

    if ( $network_id && ! is_numeric( $network_id ) ) {
        return false;
    }

    $network_id = (int) $network_id;

    // Fallback to the current network if a network ID is not specified.
    if ( ! $network_id ) {
        $network_id = get_current_network_id();
    }

    wp_protect_special_option( $option );

    /**
     * Filters the value of a specific network option before it is added.
     *
     * The dynamic portion of the hook name, `$option`, refers to the option name.
     *
     * @since 2.9.0 As 'pre_add_site_option_' . $key
     * @since 3.0.0
     * @since 4.4.0 The `$option` parameter was added.
     * @since 4.7.0 The `$network_id` parameter was added.
     *
     * @param mixed  $value      Value of network option.
     * @param string $option     Option name.
     * @param int    $network_id ID of the network.
     */
    $value = apply_filters( "pre_add_site_option_{$option}", $value, $option, $network_id );

    $notoptions_key = "$network_id:notoptions";

    if ( ! is_multisite() ) {
        $result = add_option( $option, $value, '', 'no' );
    } else {
        $cache_key = "$network_id:$option";

        // Make sure the option doesn't already exist. We can check the 'notoptions' cache before we ask for a db query
        $notoptions = wp_cache_get( $notoptions_key, 'site-options' );
        if ( ! is_array( $notoptions ) || ! isset( $notoptions[ $option ] ) ) {
            if ( false !== get_network_option( $network_id, $option, false ) ) {
                return false;
            }
        }

        $value = sanitize_option( $option, $value );

        $serialized_value = maybe_serialize( $value );
        $result = $wpdb->insert( $wpdb->sitemeta, array( 'site_id'    => $network_id, 'meta_key'   => $option, 'meta_value' => $serialized_value ) );

        if ( ! $result ) {
            return false;
        }

        wp_cache_set( $cache_key, $value, 'site-options' );

        // This option exists now
        $notoptions = wp_cache_get( $notoptions_key, 'site-options' ); // yes, again... we need it to be fresh
        if ( is_array( $notoptions ) && isset( $notoptions[ $option ] ) ) {
            unset( $notoptions[ $option ] );
            wp_cache_set( $notoptions_key, $notoptions, 'site-options' );
        }
    }

    if ( $result ) {

        /**
         * Fires after a specific network option has been successfully added.
         *
         * The dynamic portion of the hook name, `$option`, refers to the option name.
         *
         * @since 2.9.0 As "add_site_option_{$key}"
         * @since 3.0.0
         * @since 4.7.0 The `$network_id` parameter was added.
         *
         * @param string $option     Name of the network option.
         * @param mixed  $value      Value of the network option.
         * @param int    $network_id ID of the network.
         */
        do_action( "add_site_option_{$option}", $option, $value, $network_id );

        /**
         * Fires after a network option has been successfully added.
         *
         * @since 3.0.0
         * @since 4.7.0 The `$network_id` parameter was added.
         *
         * @param string $option     Name of the network option.
         * @param mixed  $value      Value of the network option.
         * @param int    $network_id ID of the network.
         */
        do_action( 'add_site_option', $option, $value, $network_id );

        return true;
    }

    return false;
}

/**
 * Removes a network option by name.
 *
 * @since 4.4.0
 *
 * @see delete_option()
 *
 * @global wpdb $wpdb
 *
 * @param int    $network_id ID of the network. Can be null to default to the current network ID.
 * @param string $option     Name of option to remove. Expected to not be SQL-escaped.
 * @return bool True, if succeed. False, if failure.
 */
function delete_network_option( $network_id, $option ) {
    global $wpdb;

    if ( $network_id && ! is_numeric( $network_id ) ) {
        return false;
    }

    $network_id = (int) $network_id;

    // Fallback to the current network if a network ID is not specified.
    if ( ! $network_id ) {
        $network_id = get_current_network_id();
    }

    /**
     * Fires immediately before a specific network option is deleted.
     *
     * The dynamic portion of the hook name, `$option`, refers to the option name.
     *
     * @since 3.0.0
     * @since 4.4.0 The `$option` parameter was added.
     * @since 4.7.0 The `$network_id` parameter was added.
     *
     * @param string $option     Option name.
     * @param int    $network_id ID of the network.
     */
    do_action( "pre_delete_site_option_{$option}", $option, $network_id );

    if ( ! is_multisite() ) {
        $result = delete_option( $option );
    } else {
        $row = $wpdb->get_row( $wpdb->prepare( "SELECT meta_id FROM {$wpdb->sitemeta} WHERE meta_key = %s AND site_id = %d", $option, $network_id ) );
        if ( is_null( $row ) || ! $row->meta_id ) {
            return false;
        }
        $cache_key = "$network_id:$option";
        wp_cache_delete( $cache_key, 'site-options' );

        $result = $wpdb->delete( $wpdb->sitemeta, array( 'meta_key' => $option, 'site_id' => $network_id ) );
    }

    if ( $result ) {

        /**
         * Fires after a specific network option has been deleted.
         *
         * The dynamic portion of the hook name, `$option`, refers to the option name.
         *
         * @since 2.9.0 As "delete_site_option_{$key}"
         * @since 3.0.0
         * @since 4.7.0 The `$network_id` parameter was added.
         *
         * @param string $option     Name of the network option.
         * @param int    $network_id ID of the network.
         */
        do_action( "delete_site_option_{$option}", $option, $network_id );

        /**
         * Fires after a network option has been deleted.
         *
         * @since 3.0.0
         * @since 4.7.0 The `$network_id` parameter was added.
         *
         * @param string $option     Name of the network option.
         * @param int    $network_id ID of the network.
         */
        do_action( 'delete_site_option', $option, $network_id );

        return true;
    }

    return false;
}

/**
 * Update the value of a network option that was already added.
 *
 * @since 4.4.0
 *
 * @see update_option()
 *
 * @global wpdb $wpdb
 *
 * @param int      $network_id ID of the network. Can be null to default to the current network ID.
 * @param string   $option     Name of option. Expected to not be SQL-escaped.
 * @param mixed    $value      Option value. Expected to not be SQL-escaped.
 * @return bool False if value was not updated and true if value was updated.
 */
function update_network_option( $network_id, $option, $value ) {
    global $wpdb;

    if ( $network_id && ! is_numeric( $network_id ) ) {
        return false;
    }

    $network_id = (int) $network_id;

    // Fallback to the current network if a network ID is not specified.
    if ( ! $network_id ) {
        $network_id = get_current_network_id();
    }

    wp_protect_special_option( $option );

    $old_value = get_network_option( $network_id, $option, false );

    /**
     * Filters a specific network option before its value is updated.
     *
     * The dynamic portion of the hook name, `$option`, refers to the option name.
     *
     * @since 2.9.0 As 'pre_update_site_option_' . $key
     * @since 3.0.0
     * @since 4.4.0 The `$option` parameter was added.
     * @since 4.7.0 The `$network_id` parameter was added.
     *
     * @param mixed  $value      New value of the network option.
     * @param mixed  $old_value  Old value of the network option.
     * @param string $option     Option name.
     * @param int    $network_id ID of the network.
     */
    $value = apply_filters( "pre_update_site_option_{$option}", $value, $old_value, $option, $network_id );

    if ( $value === $old_value ) {
        return false;
    }

    if ( false === $old_value ) {
        return add_network_option( $network_id, $option, $value );
    }

    $notoptions_key = "$network_id:notoptions";
    $notoptions = wp_cache_get( $notoptions_key, 'site-options' );
    if ( is_array( $notoptions ) && isset( $notoptions[ $option ] ) ) {
        unset( $notoptions[ $option ] );
        wp_cache_set( $notoptions_key, $notoptions, 'site-options' );
    }

    if ( ! is_multisite() ) {
        $result = update_option( $option, $value, 'no' );
    } else {
        $value = sanitize_option( $option, $value );

        $serialized_value = maybe_serialize( $value );
        $result = $wpdb->update( $wpdb->sitemeta, array( 'meta_value' => $serialized_value ), array( 'site_id' => $network_id, 'meta_key' => $option ) );

        if ( $result ) {
            $cache_key = "$network_id:$option";
            wp_cache_set( $cache_key, $value, 'site-options' );
        }
    }

    if ( $result ) {

        /**
         * Fires after the value of a specific network option has been successfully updated.
         *
         * The dynamic portion of the hook name, `$option`, refers to the option name.
         *
         * @since 2.9.0 As "update_site_option_{$key}"
         * @since 3.0.0
         * @since 4.7.0 The `$network_id` parameter was added.
         *
         * @param string $option     Name of the network option.
         * @param mixed  $value      Current value of the network option.
         * @param mixed  $old_value  Old value of the network option.
         * @param int    $network_id ID of the network.
         */
        do_action( "update_site_option_{$option}", $option, $value, $old_value, $network_id );

        /**
         * Fires after the value of a network option has been successfully updated.
         *
         * @since 3.0.0
         * @since 4.7.0 The `$network_id` parameter was added.
         *
         * @param string $option     Name of the network option.
         * @param mixed  $value      Current value of the network option.
         * @param mixed  $old_value  Old value of the network option.
         * @param int    $network_id ID of the network.
         */
        do_action( 'update_site_option', $option, $value, $old_value, $network_id );

        return true;
    }

    return false;
}

/**
 * Delete a site transient.
 *
 * @since 2.9.0
 *
 * @param string $transient Transient name. Expected to not be SQL-escaped.
 * @return bool True if successful, false otherwise
 */
function delete_site_transient( $transient ) {

    /**
     * Fires immediately before a specific site transient is deleted.
     *
     * The dynamic portion of the hook name, `$transient`, refers to the transient name.
     *
     * @since 3.0.0
     *
     * @param string $transient Transient name.
     */
    do_action( "delete_site_transient_{$transient}", $transient );

    if ( wp_using_ext_object_cache() ) {
        $result = wp_cache_delete( $transient, 'site-transient' );
    } else {
        $option_timeout = '_site_transient_timeout_' . $transient;
        $option = '_site_transient_' . $transient;
        $result = delete_site_option( $option );
        if ( $result )
            delete_site_option( $option_timeout );
    }
    if ( $result ) {

        /**
         * Fires after a transient is deleted.
         *
         * @since 3.0.0
         *
         * @param string $transient Deleted transient name.
         */
        do_action( 'deleted_site_transient', $transient );
    }

    return $result;
}

/**
 * Get the value of a site transient.
 *
 * If the transient does not exist, does not have a value, or has expired,
 * then the return value will be false.
 *
 * @since 2.9.0
 *
 * @see get_transient()
 *
 * @param string $transient Transient name. Expected to not be SQL-escaped.
 * @return mixed Value of transient.
 */
function get_site_transient( $transient ) {

    /**
     * Filters the value of an existing site transient.
     *
     * The dynamic portion of the hook name, `$transient`, refers to the transient name.
     *
     * Passing a truthy value to the filter will effectively short-circuit retrieval,
     * returning the passed value instead.
     *
     * @since 2.9.0
     * @since 4.4.0 The `$transient` parameter was added.
     *
     * @param mixed  $pre_site_transient The default value to return if the site transient does not exist.
     *                                   Any value other than false will short-circuit the retrieval
     *                                   of the transient, and return the returned value.
     * @param string $transient          Transient name.
     */
    $pre = apply_filters( "pre_site_transient_{$transient}", false, $transient );

    if ( false !== $pre )
        return $pre;

    if ( wp_using_ext_object_cache() ) {
        $value = wp_cache_get( $transient, 'site-transient' );
    } else {
        // Core transients that do not have a timeout. Listed here so querying timeouts can be avoided.
        $no_timeout = array('update_core', 'update_plugins', 'update_themes');
        $transient_option = '_site_transient_' . $transient;
        if ( ! in_array( $transient, $no_timeout ) ) {
            $transient_timeout = '_site_transient_timeout_' . $transient;
            $timeout = get_site_option( $transient_timeout );
            if ( false !== $timeout && $timeout < time() ) {
                delete_site_option( $transient_option  );
                delete_site_option( $transient_timeout );
                $value = false;
            }
        }

        if ( ! isset( $value ) )
            $value = get_site_option( $transient_option );
    }

    /**
     * Filters the value of an existing site transient.
     *
     * The dynamic portion of the hook name, `$transient`, refers to the transient name.
     *
     * @since 2.9.0
     * @since 4.4.0 The `$transient` parameter was added.
     *
     * @param mixed  $value     Value of site transient.
     * @param string $transient Transient name.
     */
    return apply_filters( "site_transient_{$transient}", $value, $transient );
}

/**
 * Set/update the value of a site transient.
 *
 * You do not need to serialize values, if the value needs to be serialize, then
 * it will be serialized before it is set.
 *
 * @since 2.9.0
 *
 * @see set_transient()
 *
 * @param string $transient  Transient name. Expected to not be SQL-escaped. Must be
 *                           167 characters or fewer in length.
 * @param mixed  $value      Transient value. Expected to not be SQL-escaped.
 * @param int    $expiration Optional. Time until expiration in seconds. Default 0 (no expiration).
 * @return bool False if value was not set and true if value was set.
 */
function set_site_transient( $transient, $value, $expiration = 0 ) {

    /**
     * Filters the value of a specific site transient before it is set.
     *
     * The dynamic portion of the hook name, `$transient`, refers to the transient name.
     *
     * @since 3.0.0
     * @since 4.4.0 The `$transient` parameter was added.
     *
     * @param mixed  $value     New value of site transient.
     * @param string $transient Transient name.
     */
    $value = apply_filters( "pre_set_site_transient_{$transient}", $value, $transient );

    $expiration = (int) $expiration;

    /**
     * Filters the expiration for a site transient before its value is set.
     *
     * The dynamic portion of the hook name, `$transient`, refers to the transient name.
     *
     * @since 4.4.0
     *
     * @param int    $expiration Time until expiration in seconds. Use 0 for no expiration.
     * @param mixed  $value      New value of site transient.
     * @param string $transient  Transient name.
     */
    $expiration = apply_filters( "expiration_of_site_transient_{$transient}", $expiration, $value, $transient );

    if ( wp_using_ext_object_cache() ) {
        $result = wp_cache_set( $transient, $value, 'site-transient', $expiration );
    } else {
        $transient_timeout = '_site_transient_timeout_' . $transient;
        $option = '_site_transient_' . $transient;
        if ( false === get_site_option( $option ) ) {
            if ( $expiration )
                add_site_option( $transient_timeout, time() + $expiration );
            $result = add_site_option( $option, $value );
        } else {
            if ( $expiration )
                update_site_option( $transient_timeout, time() + $expiration );
            $result = update_site_option( $option, $value );
        }
    }
    if ( $result ) {

        /**
         * Fires after the value for a specific site transient has been set.
         *
         * The dynamic portion of the hook name, `$transient`, refers to the transient name.
         *
         * @since 3.0.0
         * @since 4.4.0 The `$transient` parameter was added
         *
         * @param mixed  $value      Site transient value.
         * @param int    $expiration Time until expiration in seconds.
         * @param string $transient  Transient name.
         */
        do_action( "set_site_transient_{$transient}", $value, $expiration, $transient );

        /**
         * Fires after the value for a site transient has been set.
         *
         * @since 3.0.0
         *
         * @param string $transient  The name of the site transient.
         * @param mixed  $value      Site transient value.
         * @param int    $expiration Time until expiration in seconds.
         */
        do_action( 'setted_site_transient', $transient, $value, $expiration );
    }
    return $result;
}

/**
 * Register default settings available in WordPress.
 *
 * The settings registered here are primarily useful for the REST API, so this
 * does not encompass all settings available in WordPress.
 *
 * @since 4.7.0
 */
function register_initial_settings() {
    register_setting( 'general', 'blogname', array(
        'show_in_rest' => array(
            'name' => 'title',
        ),
        'type'         => 'string',
        'description'  => __( 'Site title.' ),
    ) );

    register_setting( 'general', 'blogdescription', array(
        'show_in_rest' => array(
            'name' => 'description',
        ),
        'type'         => 'string',
        'description'  => __( 'Site tagline.' ),
    ) );

    if ( ! is_multisite() ) {
        register_setting( 'general', 'siteurl', array(
            'show_in_rest' => array(
                'name'    => 'url',
                'schema'  => array(
                    'format' => 'uri',
                ),
            ),
            'type'         => 'string',
            'description'  => __( 'Site URL.' ),
        ) );
    }

    if ( ! is_multisite() ) {
        register_setting( 'general', 'admin_email', array(
            'show_in_rest' => array(
                'name'    => 'email',
                'schema'  => array(
                    'format' => 'email',
                ),
            ),
            'type'         => 'string',
            'description'  => __( 'This address is used for admin purposes, like new user notification.' ),
        ) );
    }

    register_setting( 'general', 'timezone_string', array(
        'show_in_rest' => array(
            'name' => 'timezone',
        ),
        'type'         => 'string',
        'description'  => __( 'A city in the same timezone as you.' ),
    ) );

    register_setting( 'general', 'date_format', array(
        'show_in_rest' => true,
        'type'         => 'string',
        'description'  => __( 'A date format for all date strings.' ),
    ) );

    register_setting( 'general', 'time_format', array(
        'show_in_rest' => true,
        'type'         => 'string',
        'description'  => __( 'A time format for all time strings.' ),
    ) );

    register_setting( 'general', 'start_of_week', array(
        'show_in_rest' => true,
        'type'         => 'integer',
        'description'  => __( 'A day number of the week that the week should start on.' ),
    ) );

    register_setting( 'general', 'WPLANG', array(
        'show_in_rest' => array(
            'name' => 'language',
        ),
        'type'         => 'string',
        'description'  => __( 'WordPress locale code.' ),
        'default'      => 'en_US',
    ) );

    register_setting( 'writing', 'use_smilies', array(
        'show_in_rest' => true,
        'type'         => 'boolean',
        'description'  => __( 'Convert emoticons like :-) and :-P to graphics on display.' ),
        'default'      => true,
    ) );

    register_setting( 'writing', 'default_category', array(
        'show_in_rest' => true,
        'type'         => 'integer',
        'description'  => __( 'Default post category.' ),
    ) );

    register_setting( 'writing', 'default_post_format', array(
        'show_in_rest' => true,
        'type'         => 'string',
        'description'  => __( 'Default post format.' ),
    ) );

    register_setting( 'reading', 'posts_per_page', array(
        'show_in_rest' => true,
        'type'         => 'integer',
        'description'  => __( 'Blog pages show at most.' ),
        'default'      => 10,
    ) );

    register_setting( 'discussion', 'default_ping_status', array(
        'show_in_rest' => array(
            'schema'   => array(
                'enum' => array( 'open', 'closed' ),
            ),
        ),
        'type'         => 'string',
        'description'  => __( 'Allow link notifications from other blogs (pingbacks and trackbacks) on new articles.' ),
    ) );

    register_setting( 'discussion', 'default_comment_status', array(
        'show_in_rest' => array(
            'schema'   => array(
                'enum' => array( 'open', 'closed' ),
            ),
        ),
        'type'         => 'string',
        'description'  => __( 'Allow people to post comments on new articles.' ),
    ) );

}

/**
 * Register a setting and its data.
 *
 * @since 2.7.0
 * @since 4.7.0 `$args` can be passed to set flags on the setting, similar to `register_meta()`.
 *
 * @global array $new_whitelist_options
 * @global array $wp_registered_settings
 *
 * @param string $option_group A settings group name. Should correspond to a whitelisted option key name.
 * 	Default whitelisted option key names include "general," "discussion," and "reading," among others.
 * @param string $option_name The name of an option to sanitize and save.
 * @param array  $args {
 *     Data used to describe the setting when registered.
 *
 *     @type string   $type              The type of data associated with this setting.
 *                                       Valid values are 'string', 'boolean', 'integer', and 'number'.
 *     @type string   $description       A description of the data attached to this setting.
 *     @type callable $sanitize_callback A callback function that sanitizes the option's value.
 *     @type bool     $show_in_rest      Whether data associated with this setting should be included in the REST API.
 *     @type mixed    $default           Default value when calling `get_option()`.
 * }
 */
function register_setting( $option_group, $option_name, $args = array() ) {
    global $new_whitelist_options, $wp_registered_settings;

    $defaults = array(
        'type'              => 'string',
        'group'             => $option_group,
        'description'       => '',
        'sanitize_callback' => null,
        'show_in_rest'      => false,
    );

    // Back-compat: old sanitize callback is added.
    if ( is_callable( $args ) ) {
        $args = array(
            'sanitize_callback' => $args,
        );
    }

    /**
     * Filters the registration arguments when registering a setting.
     *
     * @since 4.7.0
     *
     * @param array  $args         Array of setting registration arguments.
     * @param array  $defaults     Array of default arguments.
     * @param string $option_group Setting group.
     * @param string $option_name  Setting name.
     */
    $args = apply_filters( 'register_setting_args', $args, $defaults, $option_group, $option_name );
    $args = wp_parse_args( $args, $defaults );

    if ( ! is_array( $wp_registered_settings ) ) {
        $wp_registered_settings = array();
    }

    if ( 'misc' == $option_group ) {
        _deprecated_argument( __FUNCTION__, '3.0.0',
            /* translators: %s: misc */
            sprintf( __( 'The "%s" options group has been removed. Use another settings group.' ),
                'misc'
            )
        );
        $option_group = 'general';
    }

    if ( 'privacy' == $option_group ) {
        _deprecated_argument( __FUNCTION__, '3.5.0',
            /* translators: %s: privacy */
            sprintf( __( 'The "%s" options group has been removed. Use another settings group.' ),
                'privacy'
            )
        );
        $option_group = 'reading';
    }

    $new_whitelist_options[ $option_group ][] = $option_name;
    if ( ! empty( $args['sanitize_callback'] ) ) {
        add_filter( "sanitize_option_{$option_name}", $args['sanitize_callback'] );
    }
    if ( array_key_exists( 'default', $args ) ) {
        add_filter( "default_option_{$option_name}", 'filter_default_option', 10, 3 );
    }

    $wp_registered_settings[ $option_name ] = $args;
}

/**
 * Unregister a setting.
 *
 * @since 2.7.0
 * @since 4.7.0 `$sanitize_callback` was deprecated. The callback from `register_setting()` is now used instead.
 *
 * @global array $new_whitelist_options
 *
 * @param string   $option_group      The settings group name used during registration.
 * @param string   $option_name       The name of the option to unregister.
 * @param callable $deprecated        Deprecated.
 */
function unregister_setting( $option_group, $option_name, $deprecated = '' ) {
    global $new_whitelist_options, $wp_registered_settings;

    if ( 'misc' == $option_group ) {
        _deprecated_argument( __FUNCTION__, '3.0.0',
            /* translators: %s: misc */
            sprintf( __( 'The "%s" options group has been removed. Use another settings group.' ),
                'misc'
            )
        );
        $option_group = 'general';
    }

    if ( 'privacy' == $option_group ) {
        _deprecated_argument( __FUNCTION__, '3.5.0',
            /* translators: %s: privacy */
            sprintf( __( 'The "%s" options group has been removed. Use another settings group.' ),
                'privacy'
            )
        );
        $option_group = 'reading';
    }

    $pos = array_search( $option_name, (array) $new_whitelist_options[ $option_group ] );
    if ( $pos !== false ) {
        unset( $new_whitelist_options[ $option_group ][ $pos ] );
    }
    if ( '' !== $deprecated ) {
        _deprecated_argument( __FUNCTION__, '4.7.0',
            /* translators: 1: $sanitize_callback, 2: register_setting() */
            sprintf( __( '%1$s is deprecated. The callback from %2$s is used instead.' ),
                '<code>$sanitize_callback</code>',
                '<code>register_setting()</code>'
            )
        );
        remove_filter( "sanitize_option_{$option_name}", $deprecated );
    }

    if ( isset( $wp_registered_settings[ $option_name ] ) ) {
        // Remove the sanitize callback if one was set during registration.
        if ( ! empty( $wp_registered_settings[ $option_name ]['sanitize_callback'] ) ) {
            remove_filter( "sanitize_option_{$option_name}", $wp_registered_settings[ $option_name ]['sanitize_callback'] );
        }

        unset( $wp_registered_settings[ $option_name ] );
    }
}

/**
 * Retrieves an array of registered settings.
 *
 * @since 4.7.0
 *
 * @return array List of registered settings, keyed by option name.
 */
function get_registered_settings() {
    global $wp_registered_settings;

    if ( ! is_array( $wp_registered_settings ) ) {
        return array();
    }

    return $wp_registered_settings;
}

/**
 * Filter the default value for the option.
 *
 * For settings which register a default setting in `register_setting()`, this
 * function is added as a filter to `default_option_{$option}`.
 *
 * @since 4.7.0
 *
 * @param mixed $default Existing default value to return.
 * @param string $option Option name.
 * @param bool $passed_default Was `get_option()` passed a default value?
 * @return mixed Filtered default value.
 */
function filter_default_option( $default, $option, $passed_default ) {
    if ( $passed_default ) {
        return $default;
    }

    $registered = get_registered_settings();
    if ( empty( $registered[ $option ] ) ) {
        return $default;
    }

    return $registered[ $option ]['default'];
}
